More and more applications of LCDsxe2x80x94for example, use in automobiles, where temperatures across a range from xe2x88x9240xc2x0 C. to 100xc2x0 C. may readily occur, and also for portable devices such as cell phones and notebook PCsxe2x80x94are requiring liquid-crystal mixtures combining a very wide range of operating temperatures with a very low threshold voltage.
Consequently there is an ongoing demand for new, appropriate liquid-crystal mixtures and components of such mixtures. As described in Ichinose et al. (IDW,00, Abstr. LCT4-3) or in DE-A-100 50 071, the search is on for materials possessing at the same time both high optical anisotropy (xcex94n) and low rotational viscosity, along with other parameters such as, for example, high absolute dielectric anisotropy (xcex94xcex5) values, in addition to further application-relevant parameters.
It is an object of the present invention, therefore, to provide novel components for use in nematic or cholesteric or chiral smectic liquid-crystal mixtures which possess high absolute dielectric anisotropy values in combination with a favorable viscosity/clearing point relationship. Moreover, the compounds should be highly stable to light and UV and also to heat. Furthermore, they should be suitable for realizing high voltage holding ratios (VHRs). In addition, they should be readily available synthetically and thus potentially inexpensive.